1. Field of the Invention
The present invention relates to a developing apparatus having a plurality of developing units for use in a color copying machine and the like.
2. Description of the Related Art
As to a conventional color developing apparatus, there is known a way of developing each color to move a plurality of developing units. FIG. 1 is a schematic side view for describing the operation of such a conventional color developing apparatus. In FIG. 1, with each of developing units 200 being moved in turn towards a photoreceptor 4, when one of units 200 is situated in front of the photoreceptor 4, cam 400 is driven by a driving means so that a sleeve 300 set in the developing unit 200 is brought close to the photoreceptor 4 while keeping a certain distance, then development is performed. After that development, another one of units 200 is moved in front of the photoreceptor 4 and is brought close to the photoreceptor 4 by means of the cam 400, in the same manner as above, for development in another color.
In such a way of developing, however, there are some problems because the precise positioning of the developing unit 200 by means of driving the cam 400 causes the structure of the developing apparatus to be complex and expensive.